North American cranberries (Vaccinium macrocarpon) are a fruit that have recently been found to have a number of health benefits such as helping to preventing urinary tract infections. Thus, consumers have been encouraged to include more cranberries, either in the fruit form or in the juice form, in their diet. However, cranberries are one of the most acidic fruits and as such are very unpalatable unless they are sweetened. Cranberries have an outer skin with a thin waxy film, which makes the cranberry impermeable for exchange of sugar solutions. Thus, in the past cranberries have been infused either in the sliced or cut form, for example U.S. Pat. No. 5,320,861. It has been difficult to develop a satisfactory process for infusing whole uncut cranberries. The patent of Kato et al., U.S. Pat. No. 6,387,438, describes a method of preparing a sweetened softened cooked cranberry piece from punctured cranberries. In the described process the cranberries are frozen, punctured using precisely formed and sized needles, placed in an infusion solution having a Brix of from 45 to 65 at a fruit to syrup ratio of 1:1, and heated to temperatures up to boiling for a period of time sufficient to ensure that the sarcocarp, the interior fruit portion, of the cranberry is softened and sweetened while maintaining the outer skin layer intact with no ruptures other than from the puncture process. These cooked cranberries were not dried, instead they were cooled and packaged after the cooking step. In practical terms the resulting product would likely have to be either frozen or canned to be stable. The process of Kato et al. produces a fruit suitable for pie-filling, but unsuitable for many other food forms including ready to eat cereal. The Kato et al. patent does not disclose any method for making the resulting product shelf stable in the environment of, for example, a ready to eat cereal or granola-type bar. The cranberries disclosed in Kato et al. are not dried, are not buoyant, and are not suitable for use in ready to eat cereals and other desirable food products. The product of Kato et al. will find use only in sauces and fresh pie fillings.
It is desirable to develop a method for producing plump whole cranberries that are dried so they will be shelf stable and buoyant so that they will float in liquids such as the milk in a bowl of ready to eat cereal.